Method for detecting tungsten trioxide in tungsten concentrate

Abstract

The invention discloses a method for detecting tungsten trioxide in tungsten concentrate, and relates to the technical field of tungsten trioxide measurement. Mixing, crushing and grinding the raw ore; adding diluted hydrochloric acid and then adding ammonium chloride; adding a magnesium chloride solution until no precipitate appears, and then filtering and clarifying to obtain a reaction material liquid; carrying out vulcanization treatment on the reaction material liquid; taking quaternary ammonium salt as an extracting agent; then back extraction is performed to realize tungsten-molybdenum separation; adding ammonium chloride into the reaction material liquid, then adding diluted hydrochloric acid, and continuously adding; after fully shaking and dissolving, adding a mixed solution of perchloric acid and nitric acid until white smoke is generated to form tungstic acid; adding ammonia water for dissolving, firing, removing silicon by hydrofluoric acid, firing for multiple times, and weighing the amount of tungsten trioxide; obtaining a working curve by an absorbance spectrophotometry; according to the working curve, the mass fraction or percentage content of tungsten trioxide is converted, and the technical problem that the measured content of tungsten trioxide is affected due to the fact that the content of molybdenum and silicon in the removed tungsten concentrate is large is solved.

Description

Technical Field

[0001] The invention relates to the technical field of tungsten trioxide measurement, in particular to a method for detecting tungsten trioxide in tungsten concentrate. Background Art

[0002] Tungsten concentrate is an important tungsten ore, including wolframite and scheelite. 4 Containing WO 3 About 76%, scheelite CaWO 4 Containing WO 3 About 80%. It is the main raw material for producing tungsten compounds such as ferrotungstate, sodium tungstate, ammonium paratungstate (APT), and ammonium metatungstate (AMT).

[0003] The detection method of tungsten trioxide is disclosed in the prior art. The sample is dissolved in hydrochloric acid, nitric acid, and perchloric acid in the presence of a small amount of ammonium fluoride, and concentrated until white smoke is emitted to drive off excess fluoride ions and nitrate ions, and tungsten is precipitated as tungstic acid. After filtering, the tungstic acid is dissolved in ammonia water after being separated from most of the coexisting elements. The filtrate is evaporated and burned, and the silicon is removed with hydrofluoric acid. After burning again, the amount of tungsten trioxide is weighed. The detection steps are to determine the mass fraction of tungsten trioxide in the residue and filtrate by absorptiometry.

[0004] However, when the samples collected from existing tungsten concentrate contain more molybdenum and silicon, the results of tungsten trioxide will be too high. Since the results of existing tungsten trioxide analysis often contain a certain amount of impurity molybdenum and the content is too high, if it is not removed, the final measured tungsten trioxide grade will be too high, which will lose the accuracy of the tungsten trioxide grade. Summary of the invention

[0005] The purpose of the present invention is to make up for the deficiencies of the prior art, provide a method for detecting tungsten trioxide in tungsten concentrate, and solve the technical problem of removing the high content of molybdenum and silicon in tungsten concentrate, which affects the measurement content of tungsten trioxide.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for detecting tungsten trioxide in tungsten concentrate, comprising the following steps:

[0007] Step 1, the raw ore is mixed, crushed and ground, and the particle size is controlled to be no more than 250 mesh after screening after treatment;

[0008] Step 2, grouping into groups a1, a2, a3...an; a total of n groups; selecting samples with a mass of no less than 5g; selecting samples of equal mass to enter each reaction test tube;

[0009] Step 3, adding dilute hydrochloric acid and heating until the pH value of the solution continues to become weakly acidic; then adding ammonium chloride to further adjust the pH value to 8-9;

[0010] Step 4, adding magnesium chloride solution to make the pH value of the solution weakly alkaline until no precipitation occurs, then filtering and clarifying to obtain a reaction liquid, and washing the solid and recovering it;

[0011] Step 5, the reaction liquid is subjected to sulfurization treatment to make MoO 4 2- Converted to MoS 4 2- Then, quaternary ammonium salt was used as the extractant to extract MoS 4 2- Extract into the organic phase; then use NaClO solution to remove MoS 4 2- Oxidized to MoO 4 2- After stripping, tungsten and molybdenum are separated;

[0012] Step 6, first add ammonium chloride to the residual reaction liquid in step 5, then add dilute hydrochloric acid, and continue to add until the pH value is further adjusted to 8-9;

[0013] After fully shaking to dissolve, add a mixture of perchloric acid and nitric acid, and continue until white smoke is generated and last for 1 minute to form tungstic acid; and use water to blow the inner surface of the reaction tube, and then filter with filter paper to obtain the filtrate, and add ammonia water to dissolve, and heat in a water bath at 45-60℃;

[0014] Step 7, the filtrate is further evaporated to dryness and burned, and then desiliconized with hydrofluoric acid, and the amount of tungsten trioxide is weighed after repeated burning;

[0015] Step 8, pour the filtrate in step 7 into an iron crucible, add sodium peroxide and stir; melt in a high-temperature furnace at a temperature of not less than 720° C.; then take out the iron crucible, immerse it in water and rinse the crucible, transfer it to a volumetric flask after cooling, dilute it with water to 50 ml, and shake it well;

[0016] Transfer 10 ml of the filtrate into a colorimetric tube, add saturated oxalic acid solution to 20 ml; then add a mixed solution of hydrochloric acid-tin dichloride-potassium thiocyanate-titanium trichloride to 50 ml and shake quickly;

[0017] Step 9, using a spectrophotometer, color development for about 20 minutes at a wavelength of 430nm, and measure its absorbance; with the amount of tungsten trioxide as the horizontal coordinate and the absorbance as the vertical coordinate, a working curve is drawn to obtain the tungsten trioxide content;

[0018] Step 10, converting the mass fraction or percentage of tungsten trioxide according to the working curve of step 9.

[0019] In a further technical solution, in step 2, the groups are divided into 5 groups; each group selects 5 g of sample;

[0020] In step 3, the concentration of dilute hydrochloric acid is (0.5-2.5) mol / L, and the mass of added ammonium chloride is 1-1.8 g.

[0021] In a further technical solution, in step 4, the magnesium chloride solution is 2 mol / L, and when added, it is quantitatively added, and each time (2-5 ml) is added, an external camera is used to record and observe whether the precipitation volume increases before and after;

[0022] Then, the solution is allowed to stand for no less than 20 minutes. The solution is then filtered through a filter paper on a funnel to separate the precipitate from the solution. The solution is allowed to stand for another 15 minutes to see if clarification occurs. If precipitate is produced again, continue filtering until no obvious precipitate is produced and clarification is completed. The precipitate is washed and dried for recovery.

[0023] In a further technical solution, in step 5, a sulfiding agent is used for sulfidation, and the sulfiding agent includes sodium sulfide or hydrogen sulfide; the heating temperature is 80° C., and the pH value is 7 to 7.5.

[0024] In a further technical solution, in step 5, the quaternary ammonium salt extractant is one or more of TBP, TRPO, DAMP, and N263;

[0025] The extractant forms a complex with the molybdenum element to separate the molybdenum element from the reaction liquid.

[0026] In a further technical solution, in step 6, add 1g of ammonium chloride; then add dilute hydrochloric acid to 50ml; heat to 30-50°C and shake thoroughly for 15min; the mixed solution of perchloric acid and nitric acid has a mass ratio of 2:1 and the volume does not exceed 6ml.

[0027] In a further technical scheme, in step 8, the concentration of hydrochloric acid is 3.6 mol / L; the tin dichloride solution is 8g of stannous chloride in a beaker, 50ml of hydrochloric acid is added, heated to dissolve, cooled to room temperature, and then 350ml of hydrochloric acid is added, and diluted to 1000ml with water to obtain a hydrochloric acid-tin dichloride solution with a concentration of 8g / L; 20ml of titanium trichloride is taken, diluted to 100ml with hydrochloric acid, and 5-10 zinc gongqi particles are added, and the titanium trichloride solution is prepared; the mixing ratio is 45:1.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] Before preparing tungstic acid, the present invention preferentially reduces the content of minerals formed by silicon and molybdenum elements to reduce the interference of these elements in the measurement of tungsten trioxide. Silicon dioxide is formed by the reaction of ammonium chloride and silicate, and precipitation is carried out. Similarly, magnesium chloride will form magnesium silicate precipitation. Sulfidation extraction reduces the molybdenum content, and tungsten and molybdenum are separated by repeated extraction; then tungstic acid is prepared, tungsten trioxide is prepared by burning, and the content is detected by absorptiometry. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the detection process flow of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example

[0033] See also Figure 1 The present invention provides a technical solution, a method for detecting tungsten trioxide in tungsten concentrate, comprising the following steps:

[0034] Step 1, the raw ore is mixed, crushed and ground, and the particle size is controlled to be no more than 250 mesh after screening after treatment;

[0035] Step 2, grouping into groups a1, a2, a3...an; a total of n groups; selecting samples with a mass of no less than 5g; selecting samples of equal mass to enter each reaction test tube;

[0036] Step 3, adding dilute hydrochloric acid and heating until the pH value of the solution continues to become weakly acidic; then adding ammonium chloride to further adjust the pH value to 8-9;

[0037] Step 4, adding magnesium chloride solution to make the pH value of the solution weakly alkaline until no precipitation occurs, then filtering and clarifying to obtain a reaction liquid, and washing the solid and recovering it;

[0038] Step 5, the reaction liquid is subjected to sulfurization treatment to make MoO 4 2- Converted to MoS 4 2- Then, quaternary ammonium salt was used as the extractant to extract MoS 4 2- Extract into the organic phase; then use NaClO solution to remove MoS 4 2- Oxidized to MoO4 2- After stripping, tungsten and molybdenum are separated;

[0039] Step 6, first add ammonium chloride to the residual reaction liquid in step 5, then add dilute hydrochloric acid, and continue to add until the pH value is further adjusted to 8-9;

[0040] After fully shaking to dissolve, add a mixture of perchloric acid and nitric acid, and continue until white smoke is generated and last for 1 minute to form tungstic acid; and use water to blow the inner surface of the reaction tube, and then filter with filter paper to obtain the filtrate, and add ammonia water to dissolve, and heat in a water bath at 45-60℃;

[0041] Step 7, the filtrate is further evaporated to dryness and burned, and then desiliconized with hydrofluoric acid, and the amount of tungsten trioxide is weighed after repeated burning;

[0042] Step 8, pour the filtrate in step 7 into an iron crucible, add sodium peroxide and stir; melt in a high-temperature furnace at a temperature of not less than 720° C.; then take out the iron crucible, immerse it in water and rinse the crucible, transfer it to a volumetric flask after cooling, dilute it with water to 50 ml, and shake it well;

[0043] Transfer 10 ml of the filtrate into a colorimetric tube, add saturated oxalic acid solution to 20 ml; then add a mixed solution of hydrochloric acid-tin dichloride-potassium thiocyanate-titanium trichloride to 50 ml and shake quickly;

[0044] Step 9, using a spectrophotometer, color development for about 20 minutes at a wavelength of 430nm, and measure its absorbance; with the amount of tungsten trioxide as the horizontal coordinate and the absorbance as the vertical coordinate, a working curve is drawn to obtain the tungsten trioxide content;

[0045] Step 10, converting the mass fraction or percentage of tungsten trioxide according to the working curve of step 9.

[0046] For group testing, the groups were divided into 5 groups; 5g of sample was selected from each group; they were placed in reaction tubes of the same volume.

[0047] In step 3, the concentration of dilute hydrochloric acid is (0.5-2.5) mol / L, and the mass of added ammonium chloride is 1-1.8 g.

[0048] In step 4, the magnesium chloride solution is 2 mol / L, and when adding, it is quantitatively added, each time adding (2-5 ml), using external video recording to observe whether the precipitation volume increases before and after;

[0049] Then, the solution is allowed to stand for no less than 20 minutes. The solution is then filtered through a filter paper on a funnel to separate the precipitate from the solution. The solution is allowed to stand for another 15 minutes to see if clarification occurs. If precipitate is produced again, continue filtering until no obvious precipitate is produced and clarification is completed. The precipitate is washed and dried for recovery.

[0050] In step 5, a sulfiding agent is used for sulfidation, and the sulfiding agent includes sodium sulfide or hydrogen sulfide; the heating temperature is 80° C., and the pH value is 7 to 7.5.

[0051] In step 5, the quaternary ammonium salt extractant is one or more of TBP, TRPO, DAMP, and N263;

[0052] The extractant forms a complex with the molybdenum element to separate the molybdenum element from the reaction liquid.

[0053] In a further technical solution, in step 6, add 1g of ammonium chloride; then add dilute hydrochloric acid to 50ml; heat to 30-50°C and shake thoroughly for 15min; the mixed solution of perchloric acid and nitric acid has a mass ratio of 2:1 and the volume does not exceed 6ml.

[0054] In step 8, the concentration of hydrochloric acid is 3.6 mol / L; the tin dichloride solution is 8 g of stannous chloride in a beaker, 50 ml of hydrochloric acid is added, heated to dissolve, cooled to room temperature, and then 350 ml of hydrochloric acid is added, and diluted to 1000 ml with water to obtain a hydrochloric acid-tin dichloride solution with a concentration of 8 g / L; 20 ml of titanium trichloride is taken, diluted to 100 ml with hydrochloric acid, and 5-10 zinc gongqi particles are added, and the mixture is prepared to obtain a titanium trichloride solution; the mixing ratio is 45:1.

Claims

1. A method for detecting tungsten trioxide in tungsten concentrate, characterized in that: The following steps are involved: Step 1, the raw ore is mixed, crushed and ground, and the particle size is controlled to be no more than 250 mesh after screening after treatment; Step 2, grouping into groups a1, a2, a3...an; a total of n groups; selecting samples with a mass of no less than 5g; selecting samples of equal mass to enter each reaction test tube; Step 3, adding dilute hydrochloric acid and heating until the pH value of the solution continues to become weakly acidic; then adding ammonium chloride to further adjust the pH value to 8-9; Step 4, adding magnesium chloride solution to make the pH value of the solution weakly alkaline until no precipitation occurs, then filtering and clarifying to obtain a reaction liquid, and washing the solid and recovering it; Step 5, the reaction liquid is subjected to sulfurization treatment to make MoO4 2 -Converted to MoS4 2 -, and then use quaternary ammonium salt as extractant to extract MoS4 2 - extract into the organic phase; then use NaClO solution to remove MoS4 2 -Oxidized to MoO4 2 - Post-strip extraction to achieve separation of tungsten and molybdenum; Step 6, first add ammonium chloride to the residual reaction liquid in step 5, then add dilute hydrochloric acid, and continue to add until the pH value is further adjusted to 8-9; After fully shaking to dissolve, add a mixture of perchloric acid and nitric acid and continue until white smoke is produced and last for 1 minute to form tungstic acid; The inner surface of the reaction tube is washed with water, and then filtered with filter paper to obtain a filtrate, and ammonia water is added to dissolve it, and heated in a water bath at 45-60°C; Step 7, the filtrate is further evaporated to dryness and burned, and then desiliconized with hydrofluoric acid, and the amount of tungsten trioxide is weighed after repeated burning; Step 8, pour the filtrate in step 7 into an iron crucible, add sodium peroxide and stir; melt in a high-temperature furnace at a temperature of not less than 720° C.; then take out the iron crucible, immerse it in water and rinse the crucible, transfer it to a volumetric flask after cooling, dilute it with water to 50 ml, and shake it well; Transfer 10 ml of the filtrate into a colorimetric tube, add saturated oxalic acid solution to 20 ml; then add a mixed solution of hydrochloric acid-tin dichloride-potassium thiocyanate-titanium trichloride to 50 ml and shake quickly; Step 9, using a spectrophotometer, color development for about 20 minutes at a wavelength of 430nm, and measure its absorbance; with the amount of tungsten trioxide as the horizontal coordinate and the absorbance as the vertical coordinate, a working curve is drawn to obtain the tungsten trioxide content; Step 10, converting the mass fraction or percentage of tungsten trioxide according to the working curve of step 9.

2. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 2, the groups were divided into 5 groups; each group selected a sample of 5 g; In step 3, the concentration of dilute hydrochloric acid is (0.5-2.5) mol / L, and the mass of added ammonium chloride is 1-1.8 g.

3. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 4, the magnesium chloride solution is 2 mol / L, and when adding, it is quantitatively added, each time adding (2-5 ml), using external video recording to observe whether the precipitation volume increases before and after; Then, the solution is allowed to stand for no less than 20 minutes. The solution is then filtered through a filter paper on a funnel to separate the precipitate from the solution. The solution is allowed to stand for another 15 minutes to see if clarification occurs. If precipitate is produced again, continue filtering until no obvious precipitate is produced and clarification is completed. The precipitate is washed and dried for recovery.

4. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 5, a sulfiding agent is used for sulfidation, and the sulfiding agent includes sodium sulfide or hydrogen sulfide; the heating temperature is 80° C., and the pH value is 7 to 7.

5.

5. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 5, the quaternary ammonium salt extractant is one or more of TBP, TRPO, DAMP, and N263; The extractant forms a complex with the molybdenum element to separate the molybdenum element from the reaction liquid.

6. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 6, add 1 g of ammonium chloride; then add dilute hydrochloric acid to 50 ml; heat to 30-50°C and shake thoroughly for 15 minutes; the mixture of perchloric acid and nitric acid has a mass ratio of 2:1 and a volume not exceeding 6 ml.

7. The method for detecting tungsten trioxide in tungsten concentrate according to claim 1, characterized in that: In step 8, the concentration of hydrochloric acid is 3.6 mol / L; the tin dichloride solution is 8 g of stannous chloride in a beaker, 50 ml of hydrochloric acid is added, heated to dissolve, cooled to room temperature, and then 350 ml of hydrochloric acid is added, and diluted to 1000 ml with water to obtain a hydrochloric acid-tin dichloride solution with a concentration of 8 g / L; 20 ml of titanium trichloride is taken, diluted to 100 ml with hydrochloric acid, and 5-10 zinc gongqi particles are added, and the mixture is prepared to obtain a titanium trichloride solution; the mixing ratio is 45:1.

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